Device for disposing injection needles

Abstract: An injection syringe slot 28 for holding a tip of a syringe 30 detachably is formed on a case 2. A pair of shafts 4 and 6 connected to a rotary drive device is journalled on the case 2, and a plurality of elongate electrodes 8 and 10 are fixed to each of the shafts 4 and 6 at a predetermined interval. Each electrode 8 of the shaft 4 of one side forms a pair with each electrode 10 of the shaft 6 of the other side which is opposed to each other with a difference in level in axial direction, and a plurality of sets of a pair of electrodes are set so that the opposite interval of a pair of electrodes of a lower level is narrower than the opposite interval of a pair of electrodes in upper level. When a pair of electrodes 8 and 10 of the lowest level abuts on the needle 42, this pair of electrodes 8 and 10 is shortcircuited to cause a spark phenomenon, and the portion of the needle 42 abutting on the electrodes 8 and 10 melts and is cut off. When the needle 42 is cut off, a pair of electrodes 8 and 10 of this cut portion oscillates mutually in the crossing direction, and then, a pair of electrodes 8 and 10 of next upper level abuts on the needle 42.

Description: The present invention relates to a device for disposing injection needles in which used injection needles for medical treatment melt by means of sparks according to the preamble of claim 1. Many applications have been filed for devices for disposing injection needles by means of discharge, heat melting and the like and they have already become prior art. In the US - A - 5,138,124, a device for destructing used injection needles is disclosed in which an injection syringe is retained by hand, and a tip of the injection needle is urged against one of two rotating electrodes, and the injection needle melts by means of sparks. Also, in the US - A - 4,628,169, a structure of a device for destructing injection needles is disclosed in which an injection needle of an injection syringe is inserted into an elongate injection syringe slot while holding the injection syringe by hand, and the injection syringe is caused to slide along a longitudinal direction of the injection syringe slot while holding the injection syringe by hand, and the injection needle melts at its tip by sparks flying up between electrodes. Also, in the JP - A - 2-52652 which forms the next coming prior art, a device for disposing injection needles is disclosed in which a plurality of electrodes are simultaneously caused to make contact with the injection needle, and voltage of a predetermined level is applied to the injection needle through the plurality of electrodes, and the temperature of the injection needle is elevated by a resistance heat up to cut off the injection needle at an optional number of locations of the injection needle. Each of the devices disclosed in the above-noted US - A - 5,138,124 and US - A - 4,628,169 requires an attachment of the injection needle to the electrodes during the melting of the injection needle tip while an operator helds the injection syringe by hand. For this reason, the injection needle disposing operation is not easy, and moreover, the vibration of the sparks at the tip of the injection needle is transmitted to the hand which gives uncomfortable feeling on the part of the operator. Also, the device according to JP - A - 2-52652 for cutting the injection needle with heat melting while the plurality of electrodes are simultaneously in contact with the injection needle requires a structure of causing the plurality of electrodes to make contact with the injection needle simultaneously, and its structure becomes complicated. Furthermore, a system of causing the plurality of electrodes simultaneously to abut on the injection needle causes a problem of producing the uncertainty about which of the electrodes caused the cutoff of the injection needle, and in some cases, the cutoff occurrs initially at the root of the injection needle. When the cutoff portion drops, the injection needle is not cut into small pieces. Object of this invention is to provide a device for disposing injection needles in which an operation of melting and cutting of the injection needle may be carried out by free hand, namely, even if the operator leaves his hand off the injection syringe, after the syringe is set at an injection syringe slot, and the injection needle may be cut into small pieces from the tip toward the root in sequence. The above object is achieved by a device with the features of claim 1 according to the invention. Advantageous embodiments are described in the subclaims. The device according to the present invention is constructed in such a way that a pair of shafts connected to a rotary drive device is journalled on a case, and a plurality of elongate electrodes are fixed on each of the shafts in a horizontal direction at predetermined intervals. Each electrode of one shaft constitutes an electrode at plus side, and each electrode of the other shaft at minus side. The electrodes are opposed to form pairs respectively, and differences in height are provided so that the electrodes at the one shaft side and the electrodes at the other shaft are mutually crossed without causing any collision when they approach to each other. An opposite interval beteween an electrode at the one shaft side forming a pair with an electrode at the other shaft side is set to be narrower for the opposite interval of a pair of electrodes of lower level against the opposite interval of a pair of electrodes of higher level, and with this arrangement, the opposite interval between an electrode of the one shaft forming a pair with an electrode of the other shaft is arranged to be narrower in sequence towards the lower part of the injection needle disposed at the center of each pair of electrodes. The used syringe is set at the syringe slot of the case, and the injection needle of the syringe is disposed almost at a center of an space portion formed between the electrode group of the one side and the electrode group of the other side. When the two shafts are rotated in mutually opposite directions from a return position by means of a solenoid, a pair of electrodes of the lowest level touches the lower part of the injection needle, and the other electrode of the upper level is engaged at a position which is separated from the injection needle. When the pair of electrodes of the lowest level makes contact with the injection needle, the electrodes are shortcircuited, which produces a spark phenomenon, and the portion of the injection needle which is in contact with the pair of electrodes melts and is cut off. When an injection needle porition is cut off, the next pair of electrodes of an upper level makes contact with the injection needle. When this operation is carried out in sequence, the injection needle is cut into small pieces in sequence from the tip to the root with each predetermined portion being directed upward. In the accompanying drawings: Fig. 1 is a cross sectional view showing an internal structure of a case; Fig. 2 is a cross sectional view showing a mounting structure of electrodes; Fig. 3 is a bottom view of a case showing a rotary drive means of shafts; Fig. 4 is a drawing for explanation of a disposed conditions of electrodes; Fig. 5 is a drawing for explanation of an operation of electrodes; Fig. 6 is a plan view showing a condition where an electrode of the one side forming a pair with an electrode of the other side is crossed with the other; Fig. 7 is a drawing for explanation of an operation of this invention; and Fig. 8 is a general view of an device according to this invention. A device according to the present invention will be described in the following in detail by referring to embodiments illustrated in attached drawings. Reference numeral 2 denotes a case, and numerals 4 and 6 denote shafts rotatably supported on a top and bottom wall of the case 2 by means of a ball bearing, and they are mutually in parallel at a predetermined interval. Each of a plurality of electrodes 8 and 10 consisting of elongate plate-like small pieces is fixed to the shafts 4 and 6 at a fixed interval. A difference in level is formed in height of the electrodes 8 at the shaft 4 side, and in height of the electrodes 10 at the shaft 6 side, and the corresponding pair of electrodes 8 and 10 is arranged to be crossed as shown in Fig. 6 when they approach to each other. An opposite interval of each electrode 8 and that of each electrode 10 along the shafts 4 and 6 are set slightly wider than a thickness of the electrode. Five pieces of the electrodes 8 at the shaft 4 side are provided in this embodiment, and identical five pieces of the electrodes 10 at the other shaft 6 side are provided. The electrodes 8 are directed to an identical direction respectively, and also, the electrodes 10 are directed to an identical direction, and each of them is fixed to the shafts 4 and 6. A belt like silicon carbide 12 or a beltlike sintered graphite is fixed to opposite sides of the electrodes 8 of the shaft 4 side and that of the electrode 10 of the shaft 6 side. The electrodes 8 and 10 are of such that a width L of each is set at a wider value for the lower level electrodes, and a pair of an electrode 8 of one side and an electrode 10 of the other side has the same width L. A pair of the electrodes 8 and 10 as shown in Fig. 5, is opposed at an equal interval d against a center axis N of the opposite space portion S between the electrode 8 group of one side and the electrode 10 group of the other side. The opposite interval d based on the center axis N as a standard of a pair of the electrodes 8 and 10 is set at a narrower value for the lower level than the upper level. Namely, the interval d becomes smaller as the electrodes positioned at lower levels. Accordingly, when the shafts 4 and 6 are rotated in mutually counter directions, and the electrode 8 group of the shaft 4 side and the electrode 10 group of the shaft 6 side approach to each other, a pair of the lower electrodes 8 and 10 is piled on each other in the first place, and then, the pair of the electrodes 8 and 10 which are of next upper level are piled upon another, and the superposed conditions are arranged to shift upwards in sequence according to the rotation of the shafts 4 and 6. As shown in Fig. 3, fan-shaped gears 14 and 16 are fixed to lower portions of the shafts 4 and 6, and they are mutually meshed. Numeral 18 denotes a solenoid fixed to a lower wall of the case 2, and one end of a connecting link plate 22 is rotatably journalled on an output shaft 20 of the solenoid and the other end of the connecting link plate 22 is rotatably journalled to an eccentric portion of the fan-shaped gear 14. The fan-shaped gear 14 is energized in a clockwise direction in Fig. 3 by means of a tensile force of a return coil spring 24, and a side surface of the fan-shaped gear 14 is resiliently engaged with a stopper shaft 26 by the energizing force which is projected on a bottom surface of the case 2. Numeral 28 denotes an injection syringe slot, and is composed of a tapered guide portion 28a that opens to an upper surface of the case 2 and a taper tube like holding portion 28b for fitting and holding a tip portion 30a of an injection syringe 30 detachably. The syringe slot 28 is disposed at a center axis N in the middle of an opposite space portion 32 formed by opposing one electrode 8 and the other electrode 10. Numeral 34 denotes a blower fixed to the bottom of the case 2, and its blowing opening is opposed to a plurality of through holes (not shown in the drawing) perforated on the lower wall of the case 2. The case 2 is mounted on a cabinet 36 aslantly as shown in FIG. 8. The electrodes 8 and 10 are electrically connected to shafts 4, 6 and a power source switch provided on an operation panel of the cabinet 36 and a battery (not shown in the drawing) in the cabinet 36 by means of a boosting circuit, and each electrode 8 at the shaft 4 side is impressed with plus voltage and each electrode 10 at the shaft 6 side is impressed with minus voltage. The solenoid 18 is connected to the battery by means of a solenoid control circuit (not shown in the drawing) built in the cabinet 36, and when an operation push button switch 40 is pressed down, a solenoid drive current pulse of a predetermined pulse width is supplied to the solenoid 18 at a predetermined period, and when hand leaves the switch 40, the supply of the solenoid drive current pulse is stopped. An operation of the present embodiment will be described in the following. When the tip portion 30a of the syringe 30 provided with a needle 42 is inserted into the syringe slot 28, the tip portion 30a is retained at the holding portion 28b of the syringe slot 28. In a normal condition, the fan-shaped gear 14 is engaged with the stopper shaft 26 by the tensile force of the spring 24, and the electrode 8 group of the shaft 4 side and the electrode 10 group of the shaft 6 side are opposed at a predetermined interval. The needle 42 of the syringe 30 retained at the syringe slot 28 is positioned at a middle of the opposite space portion 32 of the electrode 8 group and the electrode 10 group. In the entire region from the tip to the root of the needle 42 of a standard dimension, as shown in FIG. 1, four sets of a pair of electrodes 8 and 10 are opposed. By the way, the pair of electrodes 8 and 10 which is positioned at the lower part of the tip of the needle 42 and not being in contact with the tip thereof is for the longer needles, and this pair of electrodes crosses with each other as shown in FIG. 6. When an operator turns the power source switch 38 on, and the operation switch 40 is pressed down, pulse current is supplied to the solenoid 18. This pulse current has a predetermined pulse width, and while the operation switch is pressed down, it is supplied to the solenoid 18 repeatedly at a predetermined period. When the solenoid 18 is energized, the output shaft 20 is attracted by the electromagnetic force, and the fan-shaped gear 14 is rotated in counterclockwise direction in FIG. 3, and accordingly, the fan-shaped gear 16 is rotated in clockwise direction. The shafts 4 and 6 are rotated by the rotation of the fan-shaped gears 14 and 16, and the electrode 8 group of one part and the electrode 10 group of the other part are oscillated in a direction where the electrode groups mutually cross (refer to FIG. 6) in the opposite condition (refer to FIG. 4) at a predetermined interval. At this time,the pair of electrodes 8 and 10 which is of the lowest level and being opposed to the needle 42 makes contact with the lower portion of the needle 42 as shown in FIG. 7A. The foregoing contact causes a short circuit (short) between the pair of electrodes 8 and 10 to flow a shortcircuit current between the electrodes 8 and 10, causing sparks, and the portion of the needle contacting with the pair of electrodes 8 and 10 melts and cut off. When the needle 42 disposed between the pair of electrodes 8 and 10 has been melted and cut off, this pair of electrodes 8 and 10 loses the support, and is subjected to the oscillation in mutually crossing directions by the drive force of the output shaft 20 of the solenoid 18, and an other pair of electrodes 8 and 10 of an upper level makes contact with the needle 42 by the oscillation as shown in FIG. 7B. The portion of the needle 42 contacting the pair of electrodes 8 and 10 melts by the sparks between the pair of electrodes 8 and 10 in contact. As described in the foregoing, each of a pair of electrodes 8 of the shaft 4 side and electrode 10 of the shaft 6 side makes contact with the needle 42 at a time by moving from the lower part to the upper part of the needle 42, and the needle 42 melts, and is cut into pieces from the lower part to the upper part, and drops downward. At this time, the needle itself is heated up to a high temperature (a temperature at which stainless steel melts is about 1500°C whereby disinfection and sterilization are achieved. When the energization to the solenoid 18 is turned off, the shafts 4 and 6 are rotated in a return direction by the tensile force of the spring 24, and the electrode 8 group and the electrode 10 group are separated from each other at a predetermined interval. The foregoing operation repeatedly goes on while the operation switch 40 is pressed down, and the needle 42 is cut into small pieces, and the needle 42 is subjected to heat treatment. The present invention has been constructed as described in the foregoing, and there is an effect that a melting operation of the needle may be performed in a free hand manner after making an insertion of the syringe into the syringe slot of the case, and moreover, the sparks fly up from the lower part of the syringe in sequence toward the upper part thereof to allow the melting and cutting of the needle into small pieces effectively.

Claims: A device for disposing injection needles in which an injection needle (42) may be sandwiched between an electrode of one side and an electrode of an other side of the device, and sparks fly up between the electrodes to melt the needle, the device having a case (2); and being further characterized by : a pair of shafts (4 and 6) which are rotatably journalled on the case (2) and which are mutually in parallel; a rotary drive means (14, 16) for synchronously driving said pair of shafts (4 and 6) by a predetermined torque in mutually counter directions; a plurality of elongate electrodes (8) of one side fixed to the first shaft (4) of the pair of shafts (4 and 6) at a predetermined interval mutually and projecting at right angles to the shaft; a plurality of elongate electrodes (10) of the other side fixed to the second shaft (6) of the pair of shafts (4 and 6) at a predetermined interval mutually and projecting at right angles to the shaft (6) and forming a plurality of pairs with each of the electrodes (8) of the one side and disposed with a difference in level relative to the electrodes (8) of the one side so that each electrode (10) of the other side may cross with an electrode (8) of the one side; a means for impressing voltage for flying up sparks between electrodes (8) of the one side and electrodes (10) of the other side; and an injection syringe slot (28) being provided on the case (2) and having a holding portion (28b) that may hold a tip portion of a syringe detachably which tip portion is then positioned on an extension of an axis at an almost center of the space between the electrodes (8) of the one side and the electrodes (10) of the other side, whereby the distance D between pairs of side surfaces of the electrodes (8) of the one side and the corresponding, opposite side surfaces of the electrodes (10) of the other side is narrowed in sequence toward the position of the lower end of the needle (42) when positioned at the center of the space between the electrodes (8 and 10). The device for disposing injection needles according to claim 1 in which a silicon carbide (12) is fixed to a side surface of the electrodes (8) of the one side and of the electrodes (10) of the other side, making contact at the needle (42). The device for disposing injection needles according to claim 1 in which a sintered graphite is fixed to a side surface of the electrodes (8) of the one side and of the electrodes (10) of the other side, making contact at the needle (42).

Inventors: MAKIHARA SHINSAKU, MAKIHARA, SHINSAKU
Applicants: ESU MAKKU CO LTD, ESU MAKKU CO. LTD.
Application year: 1994
Main classification: A61M5
IPC codes: A61M5, A61G12, B09B3